1. Field of the Invention
The present invention relates to a substantially emulsifier-free cosmetic or dermatological preparation comprising polyacrylic acid polymers, fatty alcohols and microcrystalline wax. The preparation is suitable for application to skin (in particular, wet or moist skin) and thus permits rubbing cream in while showering.
2. Discussion of Background Information
Cosmetic or dermatological preparations can be divided on the basis of their application time and their application purpose. Some products are immediately washed off after application (“rinse-off”), others are intended to remain on the skin for longer periods of time and are effective there (“leave-on”).
Cosmetic preparations for skin care are primarily developed for application to dry skin. This form of preparations are known as leave-on preparations, such as creams, lotions or body milk. Often, these are formulated as emulsions, in particular W/O, O/W, O/W/O or W/O/W emulsions.
Emulsions are generally understood as meaning heterogeneous systems which comprise two liquids that are immiscible or only miscible to a limited extent and which are usually referred to as phases. In an emulsion, one of the two liquids (water or oil) is dispersed in the form of very fine droplets in the other liquid. The liquids (pure or in the form of solutions) are present in an emulsion in a more or less fine distribution, which is generally only stable to a limited extent.
If the two liquids are water and oil and oil droplets are present in fine distribution in water, then this is an oil-in-water emulsion (O/W emulsion, e.g. milk). The basic character, for example electrical conductivity, sensory properties, ability of the continuous phase to stain, of an O/W emulsion is defined by the water. In the case of a water-in-oil emulsion (W/O emulsion, e.g. butter), the principle is reversed, the basic character here being determined by the oil.
Leave-on preparations are not suitable for application to wet or moist skin. Due to the emulsifiers present, they are able to emulsify water and, due to the lipids, in some cases leave behind an oily film.
Rinse-off preparations are designed for application under the shower or during bathing. By contrast, rinse-off preparations, however, involve to a lesser extent the care aspect as is obtained upon rubbing cream in.
It is desirable to provide a preparation which exhibits a skin care effect and can also be applied as rinse-off, for example under the shower.
One property of cosmetic products that is very important to the consumer but can only be measured quantitatively with difficulty is their texture and sensory properties. The term “texture” is understood as meaning those properties of a cosmetic which can be attributed to the constitution of the preparation, perceived by sense of feel and touch and in some cases expressed in terms of mechanical or rheological flow properties. The texture can be tested in particular by means of sensorics. The texture of cosmetic products, which can optionally be influenced with the help of additives, is of virtually identical importance to the consumer as their effects which can be ascertained objectively.
The term “sensorics” refers to the scientific discipline which deals with the evaluation of cosmetic preparations on the basis of sensory impressions. The sensory assessment of a cosmetic is made on the basis of the visual, olfactory and haptic impressions.                Visual impressions: all features that can be perceived by eye (color, shape, structure).        Olfactory impressions: all scent impressions that can be perceived upon breathing in air through the nose, which can often be differentiated into initial scent (top note), main scent (medium note, body) and after-scent (base note). The volatile substances only released upon application also contribute to the olfactory impression.        Haptic impressions: all sensations of the sense of touch which concern primarily constitution and consistency of the product.        
The sensory analysis makes use of the possibility of ascertaining the overall sensory impression of a product integrally. Disadvantages of sensory analysis are the subjectivity of the impression, the ease with which test subjects can be influenced and the considerable scattering of the results brought about as a consequence. These failings are nowadays countered by using groups of trained test subjects, mutual shielding of the testers, and statistical evaluation of the mostly extensive analytical data.
It was therefore a further object of the present invention to provide preparations which, besides the criteria customary for cosmetics such as compatibility, storage stability and the like, also offer the consumer essential, hitherto unknown cosmetic, in particular sensory, benefits. In particular, the sought preparations should be suitable for use in the body care sector, i.e. for application to the entire body and at the same time be sensorily attractive.
EP 1 390 006 A2, the entire disclosure of which is incorporated by reference herein, discloses oil-in-water emulsions for application to wet skin. The preparations of EP 1 390 006 A2 comprise water, a dispersion stabilizer, a structured oil phase and structurant, which form a stable network of distantly distributed solids in the liquids. Besides preferred inorganic structurants, solid fatty acid esters and vaseline are specified inter alia as organic structurants. Sensory modifiers specified are additionally nonionic polymers such as polyethylene oxide, polyvinyl alcohol, polyvinyl acetate pyrrolidones, anionic polymers such as polyaspartate, polymaleates and sulfonates, cationic polymers and mixtures thereof.
EP 2 174 639 A2, the entire disclosure of which is incorporated by reference herein, discloses oil-in-water emulsions for application to wet skin. The preparations comprise water-soluble polymer, pasty oils and liquid oil in combination with a large amount of glycerol. Examples of water-soluble polymers are inter alia natural polymers such as vegetable polysaccharides, animal proteins, semi-synthetic polymers such as cellulose, starch, alginates, polysaccharide derivatives, synthetic polymers such as vinyl polymers such as polyvinyl alcohol, polyvinylpyrrolidone, polyvinyl methyl ether, carboxyvinyl polymers, alkyl-modified carboxyvinyl polymers (acrylate-alkyl methacrylate copolymer, etc.) and sodium polyacrylate, and also polyethylene glycol and ethylene oxide-propylene oxide block copolymers.